===== Commands that usually I forget =====
==== Restart DNS (Flush DNS Cache in Suse) ====
service nscd restart
==== Users management for HTTP access (Suse) ====
Suse version, but I guess it's similar for other distributions. \\
In the example below, the file that contains the users (including encrypted passwords and information such as name, email, etc..) in //htpasswd.users//. \\
If //username// does not exist it's created, otherwise it's updated. \\
The command requests the password for //username//.
Nagios related example:
htpasswd2 /usr/local/nagios/etc/htpasswd.users username
==== Change Owner ====
Use the **chown** command to change owner to one or many files.
The example below change the owner of folder ''my_folder'' to //wwwrun// user and //www// group. \\
The **//-R//** parameter (recurring) analyzes //all// subfolders and files changing the owner and group as above.
chown -R wwwrun:www /srv/www/htdocs/my_folder
==== Search for installed Package ====
=== RedHat, Fedora Core, Suse Linux, CentoOs distribution ===
Use **rpm** command as follows to list all installed packages
rpm -qa
rpm -qa | grep 'package-name'
rpm -qa | grep -i '*httpd*'
=== Debian or Ubuntu Linux distribution ===
You can use **dpkg** command to list all installed packages:
dpkg --list
dpkg --list | grep 'package-name'
dpkg --list | grep -i '*php*'
==== Redirect standard output to a PC ====
If a command has a graphical output (like //yast2//) and the server has no display (or you are remotly connected via terminal emulator), it's possible to redirect the output to a different PC using the command **export**. \\
The PC must run a listener, such as Xmanager. Command example:
Format: export DISPLAY=ip_address:0.0
Example: export DISPLAY=172.28.9.231:0.0
==== Set Proxy authetication ====
To manually set the proxy with authentication, use the format:
Acquire::http::proxy "http://user:password@proxy_server:port/";
For example, to set the proxy for //apt-get// in Ubuntu, change the configuration file ///etc/apt/apt.conf//:
Acquire::http::proxy "http://user:password@my_proxy:8080/";
Acquire::ftp::proxy "ftp://user:password@my_proxy:8080/";
Acquire::https::proxy "https://user:password@my_proxy:8080/";
==== Set SMTP server (SUSE)====
In file ///etc/postfix/main.cf// add/update the key:
relayhost = my_SMTP_server.my_domain
==== Up Ethernet Interface (SUSE)====
First get the interface name with the command **ifconfig**:
ifconfig
eth0 Link encap:Ethernet HWaddr 00:50:56:B1:00:2A
inet addr:172.28.9.87 Bcast:172.28.15.255 Mask:255.255.248.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:9756009 errors:0 dropped:0 overruns:0 frame:0
TX packets:53735102 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:902184895 (860.3 Mb) TX bytes:79080496538 (75417.0 Mb)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:16662619 errors:0 dropped:0 overruns:0 frame:0
TX packets:16662619 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:8355092362 (7968.0 Mb) TX bytes:8355092362 (7968.0 Mb)
Then use the **ifup** command:
ifup eth0